Days after she wrote to Prime Minister objecting to NIB, which would be empowered to give speedy clearances to mega projects bypassing various ministries, Natarajan refused to elaborate on the issue to a volley of questions from reporters.

"We will speak to the Prime Minister about the reservations we have on the issue. Whatever I have to say, I will say it in the Cabinet... to the Prime Minister," she said.

"But I will protect the interest of the environment," the Minister said.

In her letter to Prime Minister, Natarajan has said the manner in which changes have been sought on the issue of granting project approvals was disturbing and she wondered why NIB should step in when decisions like green clearances have to be given by her Ministry.

She also said the NIB has no constitutional authority and that the proposal will decimate the role of the Environment Ministry.